7
13. Function switch
Used to set the MOH ASSIGN, MUTE RECEIVE,
and AUTO MUTE functions, and to select MIC or
LINE 1.
• DIP switch 1
Set to ON to output MIC/LINE 1 input to the
MOH output.
• DIP switch 2
Set to ON to output LINE 2 input to the MOH
output.
• DIP switch 3
Set to ON to output LINE 3 input to the MOH
output.
• DIP switch 4
Not used.
• DIP switch 5
Set to ON to place the LINE 2 input in Mute
Receive mode.
• DIP switch 6
Set to ON to place the LINE 3 input in Mute
Receive mode.
• DIP switch 7
Set to ON to place the MIC/LINE 1 input in
Mute Send mode (audio signal-activated
muting mode).
• DIP switch 8
Set to ON to switch the MIC/LINE 1 gain to
MIC (–60 dB).
Set to OFF to switch the MIC/LINE 1 gain to
LINE 1 (–10 dB).
Notes
• Switches 1 – 8 are set to the OFF position by
default.
• Be sure to turn off the power before performing
these settings. Failure to do so may cause the
loud noise to be generated or unit failure.
14. Mute sensitivity control
Adjusts the threshold level for the MIC/LINE 1
input to activate the mute function. Turn
clockwise to increase the threshold level (lower
sensitivity), and counterclockwise to decrease it
(higher sensitivity).
Note
The audio signal level to activate muting is
independent of input volume settings. So, the
Mute Receive input is muted if a signal enters
the MIC/LINE 1 input even when the input
volume is turned down. To avoid unwanted
muting caused by unintentional inputs such as
background noise and noise sound, it is
recommended to cut the audio signal at the input
equipment (such as a microphone with talk
switch).
15. Manual mute terminal
Closing between (+) and (–) terminals mutes the
input signal set for Mute Receive by the Function
switch (13).
Opening between (+) and (–) terminals returns
the previously muted signal gradually to its
original level.
Notes
• This function is active regardless of the
Automatic mute ON/OFF setting using the
Function switch (13).
• This function is not active for the MOH output
terminal.
16. Microphone/Line 1 input terminal
600 Ω, –60 dB* (MIC)/–10 dB* (LINE 1),
electronically-balanced, removable terminal
block.
Use the Function switch (13) to select either
Microphone or Line 1.
Connect a microphone or sound source
equipment.
17. Functional ground terminal
Hum noise may be generated when external
equipment is connected to the unit. Connecting
this terminal to the functional ground may reduce
the hum noise.
Note: This terminal is not for protective earth.
18. AC power cord
Connect this cord to an AC wall outlet.
19. Speaker output terminal
4 Ω, 25 V and 70 V outputs, removable terminal
block.
Connects to speakers.
Refer to p. 9.
20. Line output terminal
600 Ω, 0 dB*, unbalanced, removable terminal
block.
Note
Bass and treble controls are not active for this
output.
21. Line 3 input terminals
10 kΩ, –10 dB*, unbalanced, removable terminal
block and RCA jacks (Upper and lower RCA
inputs are internally, passively mixed).
Connect a sound source equipment such as a
CD player.
22. Line 2 input terminals
10 kΩ, –10 dB*, unbalanced, removable terminal
block and RCA jacks (Upper and lower RCA
inputs are internally, passively mixed).
Connect a sound source equipment such as a
CD player.
* 0 dB = 1 V